Accessory devices may be used to provide a protective cover for electronic devices. The protection afforded by an accessory device may be a function of thickness of the accessory device. For example, when the electronic device is disposed in the accessory device and receives a load or force in accordance with dropping the electronic device, an accessory device having a greater thickness may offer better protection to an electronic device than another accessory device of a lesser thickness. This may be due in part to additional material afforded by the greater thickness.
However, accessory devices of greater thickness may have drawbacks. For example, an accessory device having multiple sidewalls designed to secure an electronic device may become too rigid due to the additional thickness, creating difficulty in inserting or extracting the electronic device. Also, design changes to the electronic device may render the accessory device insufficient for providing protection.